UNFAIR BOSS FIGHT

I was battling Juton brothers for about 30 minutes. I died and my friends couldn't heal. So, they told me to leave the game by the esc button in battle. Then, we defeated the brothers and it said i still needed to defeat them. Is there a way I can get my quest confirmed from the administrator or something? My Wizard is named Brandon BoomBreaker. I am level 44. Please help me, anybody.